היסטוריה של שיטות המדידה – הבדלי גרסאות

==שיטות מדידה קדומות==

שיטת המדידה הקדומות ביותר הידועות לנו כיום מקורן ב[[האלף הרביעי לפנה"ס|אלף הרביעי לפנה"ס]], ב[[מצרים]], [[מסופוטמיה]] וב[[עמק ההינדוס]]. באיזורים אלה יצרו התרבויות הראשונות מערכת של שיטות מדידה לצרכי מסחר, בניה ואמנות. שיטות אלה הגיעו לדיוק רב במדידת [[אורך]], [[מסה]] ו[[זמן]].

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The earliest known uniform systems of weights and measures seem all to have been created at some time in the [[4th millennium BC|4th]] and [[3rd millennium BC|3rd millennia BC]] among the ancient peoples of [[Egypt]], [[Mesopotamia]] and the [[Indus Valley]], and perhaps also [[Elam]] (in [[Iran]]) as well. The most astounding of these ancient systems was perhaps that of the [[Indus Valley Civilization]] (ca. 2600 BC). The Indus Valley peoples achieved great accuracy in measuring length, mass, and time. Their measurements were extremely precise since their smallest division, which is marked on an ivory scale found in [[Lothal]], was approximately 1.704 mm, the smallest division ever recorded on a scale of the [[Bronze Age]]. The [[decimal]] system was used. [[Harappa]]n engineers followed the decimal division of measurement for all practical purposes, including the measurement of mass as revealed by their hexahedron weights. Weights were based on units of 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, and 500, with each unit weighing approximately 28 grams, similar to the [[English unit|English ounce]] or Roman uncia, and smaller objects were weighed in similar ratios with the units of 0.871.

By studying the evidence given by all available sources, and by correlating the relevant facts, we obtain some idea of the origin and development of the units. We find that they have changed more or less gradually with the passing of time in a complex manner because of a great variety of modifying influences. We find the units modified and grouped into measurement systems: the Babylonian system, the Egyptian system, the Phileterian system of the [[Ptolemaic dynasty|Ptolemaic]] age, the Olympic system of Greece, the Roman system, and the [[English unit|British system]], to mention only a few.

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==היסטוריה של יחידות מדידה==

=== יחידות אורך===